Olmsted County is a county located in the U.S. state of Minnesota, founded in 1855. As of 2000, the population was 124,277. Its county seat and largest city is Rochester. Olmsted County is part of the Rochester, MN Metropolitan Statistical Area.
According to the U.S. Census Bureau, the county has a total area of 654 square miles (1,695 kmē), of which 653 square miles (1,691 kmē) is land and 1 square mile (4 kmē) (0.23%) is water. It is one of four counties in the state with no natural lakes.
Official Olmsted County website